Effect of exposure to cadmium on the hippocampus in adult albino rat and the possible role of L‑carnitine

Background The hippocampus is an important structure for formation of new memories. Cadmium is one of the most toxic agents that can affect hippocampal neurons. L‑carnitine is an antioxidant. Aim of work To demonstrate the effects of cadmium on principal cells of hippocampus of adult rats and possible protective role of L‑carnitine. Materials and methods A total of 42 adult rats aged 1 month were subdivided into four subgroups: group I was the control group, which received no treatment. Group II was administered cadmium given at a dose of 4 mg/kg/day for 1 month. Group III (sham control) was administered L‑carnitine given at a dose of 200 mg/kg/day for 1 month. Group IV was administered cadmium and L‑carnitine given to the rats at the same previous doses and duration. For each group, six rats were used for light microscopic study (gallocyanin chrom alum stain), and six rats were used for electron microscopy (group III studied only by light microscopy). Principal cell count and thickness were measured and statistically analyzed. Results Principal cells in group II showed degenerative changes. Morphometric data showed a significant decrease in measured parameters. In group III, the results were similar to those of the control group. In group IV, semithin sections and the ultrastructure of the principal cells showed obvious improvement of cells. Morphometric data also increased compared with those treated with cadmium. Conclusion Cadmium induces changes in the structure of the principal cells of the hippocampus in adult rats. L‑carnitine plays an important in protection of the hippocampus.